? Onychothemis rihai Prokop et al., 2003

(Figure 6 (a, b))

Material

Specimen no. TN1 stored in private collection of Mgr. Tomáš Novotný, Nástup Tušimice quarry, Czech Republic.

Age and outcrop

Early Miocene (Burdigalian), Libouš mine (Figure 1), Spořice district, Most Basin, Most Formation, Libkovice Member, about 15 – 20 m above the Crandallite Horizon C1 sensu Matys-Grygar & Mach (2013).

Description

Fore wing. Wing hyaline, 51.6 mm long; distance between base and nodus 26.6 mm; between nodus and apex 25.3 mm, nodus nearly midway between base and apex; distance between nodus and pterostigma 16.3 mm, between pterostigma and apex 4.3 mm; pterostigma 5.9 mm long, 0.9 mm wide, with costal and posterior sides maximally widened in middle; no oblique pterostigmal brace; pterostigma covering three and a half cells; 11 postnodal cross-veins, not well aligned with eight corresponding postsubnodal cross-veins; ‘ libellulid gap ’ long; second oblique cross-vein between RP1 and RP2 only weakly oblique; 15 preserved antenodal cross-veins of first row, apparently all well aligned with those of second row, last antenodal cross-vein incomplete; distance between first antenodal crossvein and wing base 6.9 mm; distance between arculus and wing base 5.6 mm; arculus opposite an antenodal cross-vein (probably second one, but incompletely preserved); number of cross-veins between RA and RP, between arculus and nodus, unknown; one preserved Bq cross-vein between IR2 and RP2; distance between arculus and nodus 20.6 mm; base of RP 3/4 and that of IR2 16.9 mm distal of arculus; sectors of arculus (bases of RP and MA) clearly fused basally; median and submedian spaces free of crossveins, subdiscoidal cell 3.6 mm long, 2.2 mm wide and divided into five cells; discoidal triangle narrow transverse, divided into two cells, length of its costal side 1.3 mm; proximal side 4.3 mm long, distal side 5.0 mm long; 2 – 3 rows of cells in anal area; 3 – 5 rows of cells in cubito-anal area, width of cubito-anal area 2.5 mm; CuA not well defined and reaching posterior wing margin about 3.0 mm basal of nodus; MP nearly straight and reaching posterior wing margin 3.2 mm distal of nodus; four rows of cells in postdiscoidal area just distal of discoidal triangle; postdiscoidal area narrower (2.8 mm wide) in its middle part than near discoidal triangle (3.9 mm wide); Mspl straight, with one row of cells between it and MA; RP 3/4 and MA basally nearly straight but distally curved and nearly perpendicular to posterior wing margin; RP2 aligned with subnodus; oblique cross-vein ‘ O ’ 1.1 mm distal of subnodus; IR2 and RP2 with two strong undulations; IR2 and RP2 distally curved and nearly perpendicular to wing margin; area between IR2 and RP3/4 rather wide, with a nearly straight vein Rspl; two rows of cells between Rspl and IR2; area between RP1 and RP2 rather wide, but incompletely preserved, no visible ‘ reversed libellulid oblique vein ’ between RP2 and RP3/4.